// IGNORE_BACKEND: JS_IR, JS

inline fun checkNPE(body: () -> Unit) {
    var throwed = false
    try {
        body()
    } catch (e: NullPointerException) {
        throwed = true
    }
    check(throwed)
}

fun notNullString(): String = js("'abc'")

fun notNull2String(): String = js("null")

fun nullString(): String? = js("'abc'")

fun null2String(): String? = js("null")

fun testString() {
    check(notNullString() == "abc")
    checkNPE { notNull2String() }
    check(nullString() == "abc")
    check(null2String() == null)
}

external interface ExternRef

fun notNullExternRef(): ExternRef = js("'abc'")

fun notNull2ExternRef(): ExternRef = js("null")

fun nullExternRef(): ExternRef? = js("'abc'")

fun null2ExternRef(): ExternRef? = js("null")


fun testExterRef() {
    check(notNullExternRef() != null)
    checkNPE { notNull2ExternRef() }
    check(nullExternRef() != null)
    check(null2ExternRef() == null)
}

class DataRefImpl
typealias DataRef = JsReference<DataRefImpl>

fun notNullDataRef(x: DataRef): DataRef = js("x")

fun notNull2DataRef(x: DataRef): DataRef = js("null")

fun nullDataRef(x: DataRef): DataRef? = js("x")

fun null2DataRef(x: DataRef): DataRef? = js("null")

fun testDataRef() {
    val dataRef = DataRefImpl().toJsReference()
    check(notNullDataRef(dataRef) == dataRef)
    checkNPE { notNull2DataRef(dataRef) }
    check (nullDataRef(dataRef) == dataRef)
    check (null2DataRef(dataRef) == null)
}

fun notNullInt(): Int = js("123")

fun notNull2Int(): Int = js("null")

fun nullInt(): Int? = js("123")

fun null2Int(): Int? = js("null")

fun testInt() {
    check(notNullInt() == 123)
    check(notNull2Int() == 0)
    check(nullInt() == 123)
    check(null2Int() == null)
}

fun notNullBoolean(): Boolean = js("true")

fun notNull2Boolean(): Boolean = js("null")

fun nullBoolean(): Boolean? = js("true")

fun null2Boolean(): Boolean? = js("null")

fun testBoolean() {
    check(notNullBoolean() == true)
    check(notNull2Boolean() == false)
    check(nullBoolean() == true)
    check(null2Boolean() == null)
}

fun notNullShort(): Short = js("123")

fun notNull2Short(): Short = js("null")

fun nullShort(): Short? = js("123")

fun null2Short(): Short? = js("null")

fun testShort() {
    check(notNullShort() == 123.toShort())
    check(notNull2Short() == 0.toShort())
    check(nullShort() == 123.toShort())
    check(null2Short() == null)
}

fun notNullFloat(): Float = js("123.5")

fun notNull2Float(): Float = js("null")

fun nullFloat(): Float? = js("123.5")

fun null2Float(): Float? = js("null")

fun testFloat() {
    check(notNullFloat() == 123.5f)
    check(notNull2Float() == 0.0f)
    check(nullFloat() == 123.5f)
    check(null2Float() == null)
}

fun box(): String {
    testString()
    testExterRef()
    testDataRef()
    testInt()
    testBoolean()
    testShort()
    testFloat()
    return "OK"
}